/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @author Vladimir N. Molotkov, Stepan M. Mishura
 */

package org.apache.harmony.security.asn1;

import java.io.IOException;

import org.apache.harmony.security.internal.nls.Messages;

/**
 * This class represents explicitly tagged ASN.1 type.
 * 
 * @see http://asn1.elibel.tm.fr/en/standards/index.htm
 */

public final class ASN1Explicit extends ASN1Constructured {

	/**
	 * Tagged type
	 */
	public final ASN1Type type;

	/**
	 * Constructs explicitly tagged ASN.1 type with context-specific tag class
	 * and specified tag number.
	 * 
	 * @param tagNumber
	 *            - ASN.1 tag number
	 * @param type
	 *            - ASN.1 type to be tagged
	 * @throws IllegalArgumentException
	 *             - if tagNumber is invalid
	 */
	public ASN1Explicit(int tagNumber, ASN1Type type) {
		this(CLASS_CONTEXTSPECIFIC, tagNumber, type);
	}

	/**
	 * Constructs explicitly tagged ASN.1 type.
	 * 
	 * @param tagClass
	 *            - ASN.1 tag class.
	 * @param tagNumber
	 *            - ASN.1 tag number
	 * @param type
	 *            - ASN.1 type to be tagged
	 * @throws IllegalArgumentException
	 *             - if tagClass or tagNumber is invalid
	 */
	public ASN1Explicit(int tagClass, int tagNumber, ASN1Type type) {
		super(tagClass, tagNumber);

		this.type = type;
	}

	//
	//
	// Decode
	//
	//

	@Override
	public Object decode(BerInputStream in) throws IOException {
		if (constrId != in.tag) {
			throw new ASN1Exception(Messages.getString("security.13F", //$NON-NLS-1$
					new Object[] { in.tagOffset, Integer.toHexString(constrId),
							Integer.toHexString(in.tag) }));
		}
		in.next();

		in.content = type.decode(in);

		if (in.isVerify) {
			return null;
		}
		return getDecodedObject(in);
	}

	//
	//
	// Encode
	//
	//

	@Override
	public void encodeContent(BerOutputStream out) {
		out.encodeExplicit(this);
	}

	@Override
	public void setEncodingContent(BerOutputStream out) {
		out.getExplicitLength(this);
	}

	@Override
	public String toString() {
		// FIXME fix performance
		return super.toString() + " for type " + type; //$NON-NLS-1$
	}
}